Debt Securities Available for Sale (Tables)

12 Months Ended

Dec. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Debt securities, available-for-sale

Debt securities available for sale at December 31, 2022 and 2021 are summarized as follows:

	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)		Fair Value
			(In thousands)
U.S. government and agency obligations	$	67,771	$	—	$	(4,205)	$	63,566
Mortgage-backed securities and collateralized mortgage obligations	1,351,929		135		(170,337)		1,181,727
Municipal obligations	3,697		—		(122)		3,575
Corporate debt securities	92,544		6		(12,784)		79,766
	$	1,515,941	$	141	$	(187,448)	$	1,328,634

	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)		Fair Value
			(In thousands)
U.S. government and agency obligations	$	34,711	$	404	$	(236)	$	34,879
Mortgage-backed securities and collateralized mortgage obligations	1,553,491		14,141		(13,273)		1,554,359
Municipal obligations	4,159		20		—		4,179
Corporate debt securities	109,018		2,378		(966)		110,430
Trust preferred securities	—		—		—		—
	$	1,701,379	$	16,943	$	(14,475)	$	1,703,847

Investments classified by contractual maturity date

The amortized cost and fair value of debt securities available for sale at December 31, 2022, by contractual final maturity, is shown below. Expected maturities may differ from contractual maturities due to prepayment or early call options exercised by the issuer.

	December 31, 2022
	Amortized Cost		Fair Value
	(In thousands)
One year or less	$	921	$	906
More than one year to five years	84,351		79,080
More than five years to ten years	78,740		66,921
	$	164,012	$	146,907
Mortgage-backed securities and collateralized mortgage obligations	1,351,929		1,181,727
	$	1,515,941	$	1,328,634

Expected maturities may differ from contractual maturities due to prepayment or early call options exercised by the issuer.

	December 31, 2022
	Amortized Cost		Fair Value
	(In thousands)
More than one year to five years	$	19,875	$	18,399
More than five years to ten years	19,996		16,703
More than ten years	10,000		7,465
	49,871		42,567
Mortgage-backed securities and collateralized mortgage obligations	371,652		327,824
	$	421,523	$	370,391

Debt securities, available-for-sale, unrealized loss position, fair value

The following tables summarize the fair value and gross unrealized losses of those securities that reported an unrealized loss at December 31, 2022 and 2021 and if the unrealized loss position was continuous for the twelve months prior to those respective dates:

	December 31, 2022
	Less Than 12 Months				12 Months or Longer				Total
	Fair Value		Gross Unrealized (Losses)		Fair Value		Gross Unrealized (Losses)		Fair Value		Gross Unrealized (Losses)
	(In thousands)
U.S. government and agency obligations	$	47,956	$	(2,359)	$	15,610	$	(1,846)	$	63,566	$	(4,205)
Mortgage-backed securities and collateralized mortgage obligations	424,328		(29,013)		741,515		(141,324)		1,165,843		(170,337)
Municipal obligations	3,574		(122)		—		—		3,574		(122)
Corporate debt securities	46,751		(5,792)		31,008		(6,992)		77,759		(12,784)
	$	522,609	$	(37,286)	$	788,133	$	(150,162)	$	1,310,742	$	(187,448)

	December 31, 2021
	Less Than 12 Months				12 Months or Longer				Total
	Fair Value		Gross Unrealized (Losses)		Fair Value		Gross Unrealized (Losses)		Fair Value		Gross Unrealized (Losses)
	(In thousands)
U.S. government and agency obligations	$	14,488	$	(236)	$	—	$	—	$	14,488	$	(236)
Mortgage-backed securities and collateralized mortgage obligations	820,746		(11,892)		62,407		(1,381)		883,153		(13,273)
Corporate debt securities	29,221		(671)		4,705		(295)		33,926		(966)
	$	864,455	$	(12,799)	$	67,112	$	(1,676)	$	931,567	$	(14,475)

Debt securities, available-for-sale, allowance for credit loss

The following table presents the activity in the allowance for credit losses on debt securities available for sale for the year ended December 31, 2022:

	December 31, 2022
	(In thousands)
Allowance for Credit Losses:
Beginning balance	$	—
Impact of adopting ASU 2016-13 (CECL) effective January 1, 2022	490
(Reversal of) credit losses	(490)
Balance at December 31, 2022	$	—